Ceramic coated conductor roll



Jan. 12, 1965 J. T. SHAPLAND/ ,1

CERAMIC COATED CONDUCTOR ROLL? Filed Sept. 11, 1 9 61 INVENTO/P JAMES 7'. SHAPLA/VD Br flaw/5% L4 from ey United States Patent 3,165,179 CERAMHI CQATED CONDUCTGR RULE James T. Shapiand, Pittsburgh, Pa, assignor to United States Steel Corporation, a corporation of New Jersey Filed Sept. 11, 1961, Ser. No. 137,422

12 Claims. (Cl. 1911) This application, which is a continuation-in-part of my co-pendiug application Serial No. 76,053, filed December 15, 1960, now abandoned, relates to a ceramic coated conductor roll and more particularly to such a conductor roll for use in electro-plating lines such as electrolytic tinning lines. An electrolytic tinning line in which the conductor roll has proved to be particularly useful is shown schematically on page 638 of The Making, Shaping and Treating of Steel, 7th edition, which is published by United States Steel Corporation. In the processing of such strip it is passed through a cleaning tank, a pickling tank, a scrubber, tin plating tanks, drag-out tank, spray rinse tank, a mufile furnace where the tin is reilowed, water quench tank, anodic-cathodic treatment tank, water spray tank and oiler. During the travel of the strip through the processing line it is supported on rolls, some of which must be conductor rolls and others of which are preferably conductor rolls. If the roll on the exit side of the pickling tank is the usual metal conductor roll it will be rapidly attacked by anodic action. On the other hand, if a non-conductor roll is used at this point and a conductor roll is used after the rinse the life of the roll will be longer, but a higher voltage will be necessary to maintain the desired current in the strip passing through the acid in the pickling tank. The rolls in the tin plating tank must be conductor rolls and when the usual metal rolls are used there is danger that they will pick up tin which can build up on the rolls to such an extent that the strip will be damaged. Also, the metal rolls have a very low co-eflicient of friction so that slippage can occur between the roll and the strip. There is also a possibility of tin sticking to the rolls after the tin plating. This is particularly true of the roll or rolls in the mufile furnace or melting tower which carry the strip at temperatures above room temperature. This elevated temperature increases the possibility of tin pick-up and it is common to use non-conductor rolls, such as silicone rubber rolls whereas a conductor roll would improve the process.

It is therefore an object of my invention to provide a ceramic coated conductor roll which is abrasive and corrosion resistant.

Another object is to provide such a roll which has a higher co-efiicient of friction than metal rolls.

Still another object is to provide such a roll which will not pick up metal in electro-plating processes.

These and other objects will be more apparent after referring to the following specification and attached drawing, in which:

FIGURE 1 is a view of a longitudinal section of the conductor roll of my invention; and

FIGURE 2 is a view taken on the line IIII of FIG- URE 1.

Referring more particularly to the drawing reference numeral 2 indicates the body of the conductor roll which is supported by shaft sections 4. The roll body 2 must be made of conducting material and is preferably copper, but carbon or other metal may also be used. A conductive metal coating 6 is preferably provided over the body 2. A conductive ceramic coating 8 is applied over the coating 6 and is preferably partly reduced titanium dioxide. This may vary somewhat in composition, but generally includes Ti O and TiO The purpose of the coating 6 is to increase the adherence of the coating 8 and when used the coating 6 is a nickel containing substance, preferably nickel or nickel chromium alloy. The coatings 6 and 8 may be applied to the rolls in any known manner, but are preferably applied by the flame spraying process described in Bradstreet Patents Nos. 2,904,449, dated September 15, 1959, and 2,908,502, dated October 13, 1959. In applying the coating 8 in this manner TiO may be used as it will be partially reduced by the process. In applying the coatings'the peripheral surface of the roll body 2 is first roughened such as by sand or grit blasting to improve the adherence of the coating, In a particular roll 50 mesh grit has been used. Prior to applying the metal the roll may be heated in a dryer at approximately 220 F. The coatings 6 and 8 are then applied as described in the mentioned patents. The thickness of the coating 6 has very little effect on the properties of the roll. However, the metal coating 6 need not be thick and thicknesses between .0005 and .002" have proved satisfactory. The thickness of the ceramic coating 8 may also vary and thicknesses between 0.001 and 0.020" are satisfactory, but the adherence was not as good when the coating thickness was above 0.01". It will be apparent that the thicknesses of coatings s and 8 are greatly exaggerated for the purpose of illustration. In order to reduce porosity the coated roll may be washed with a solution, such as aluminum phosphate dried at 500 F.

The plasma flame coating process may also be used in applying the coatings 6 and 8. In this process electrical power is converted into heat by dissociating and partially ionizing inert gas with an arc. The gases recombine at the spray gun, releasing heat to melt the powdered oxide or metal being sprayed. The powdered material is projected into'the spray gun by a nitrogen carrier gas.

Power may be applied to the conductor roll in any usual manner such as by means of a brush 10 bearing against the side of roll body 2.

While one embodiment of my invention has been shown and described, it will be apparent that other adaptations and modifications may be made without departing from the scope of the following claims.

I claim:

1. A ceramic coated conductor roll for supporting an object passing thereover comprising a cylindrical roll body made of electrically conductive material, a shaft supporting said roll body, and a thin object supporting coating of electrically conductive ceramic material on the outer surface of said roll body.

2. A ceramic coated conductor roll for supporting an object passing thereover comprising a cylindrical roll body made of electrically conductive material, a shaft supporting said roll body, and a thin object supporting coating of electrically conducting titanium oxide on the outer surface of said roll body.

3. A ceramic coated conductor roll for supporting an object passing thereover comprising a cylindrical roll body made of electrically conductive material, a shaft supporting said roll body, an electrically conductive coating of a nickel containing material on the outer surface of said roll body, and a thin object supporting coating of electrically conductive ceramic material on said nickel containing coating.

4. A ceramic coated conductor roll for supporting an object passing thereover comprising a cylindrical roll body made of electrically conductive material, a shaft supporting said roll body, an electrically conductive coating of a nickel containing material on the outer surface of said roll body, and a thin object supporting coating of electrically conducting titanium oxide on said nickel containing coating.

5. A ceramic coated conductor roll for supporting an object passing thereover comprising a cylindrical roll body made of electrically conductive material, a shaft supporting said roll body, a roughened outer surface on'said roll body, an electrically conducting coating of a nickel containing material on said roughened outer surface, and a thin object supporting coating of electrically conducting titanium oxide on said nickel containing 7 coating.

body is a member of the class consisting of copper and carbon, and the thickness of the ceramic coating is between .001 and .020 inch.

8. A ceramic coated conductor roll according to claim 2 in which the electrically conductive material of the roll body is a member of the class consisting of copper and carbon, and the thickness of the titanium oxide coating is between .001 and .020 inch.

9. A ceramic coated conductor roll according to claim -3 in which the electrically conductive material of the roll body is a member of the class consisting of copper and carbon, and the thickness of the ceramic coating is between .001 and .020 inch.

10. A ceramic coated conductor roll according to claim 4 in which the electrically conductive material of i the roll body is a member of the class consisting of copper and carbon, and the thickness of the titanium oxide coating is between .001 and .020 inch.

11. A ceramic coated conductor roll according to claim 5 in which the electrically conductive material of the roll body is a member of the class consisting of copper and carbon, and the thickness of the titanium oxide coating is between .001 and .020 inch.

12. A ceramic coated conductor roll according to claim 6 in which the electrically conductive material of the roll body is a member of the class consisting of copper and carbon, and the thickness of the titanium oxide coating is between .001 and .020 inch.

References Cited in the file of this patent UNITED STATES PATENTS 2,151,048 Rowe Mar. 21, 1939 2,266,347 Watson Dec. 16, 1941 2,864,884 Counts et al Dec. 16, 1958 2,958,742 Faimer Nov, 1, 1960 3,001,893 Kreuchen Sept. 26, 1961 3,020,182 Daniels Feb. 6, 1962 3,035,944 Sher et a1. May 22, 1962 3,061,461 Le Hovec et a1. Oct. 30, 1962 FOREIGN PATENTS 617,369 Canada Mar. 28, 1961 817,233 Great Britain July 29, 1959 OTHER REFERENCES Brand et al., German application 1,086,616, printed Aug. 4, 1960 (K1. 80 13 23/03), 3 pps. spec., no drwg. 

1. A CERAMIC COATED CONDUCTOR ROLL FOR SUPPORTING AN OBJECT PASSING THEREOVER COMPRISING A CYLINDRICAL ROLL BODY MADE OF ELECTRICALLY CONDUCTIVE MATERIAL, A SHAFT SUPPORTING SAID ROLL BODY, AND A THIN OBJECT SUPPORTING COATING OF ELECTRICALLY CONDUCTIVE CERAMIC MATERIAL ON THE OUTER SURFACE OF SAID ROLL BODY. 